The United States (U.S.) legal system includes several major bodies of legal texts which outline the authorities and responsibilities of federal government agencies such as the IRA, VA, DISA, Air Force, GPO, CTH, USAID, FAA, and DOD. Congress can introduce and pass various bills and resolutions which can affect the scope of these federal agencies. These enacted bills become public laws and a part of the United States Code (U.S.C.) is modified to incorporate these public law. These changes to the U.S.C. can create and eliminate agencies, modify their funding, and/or expand or contract their jurisdiction. One of the main roles of federal agencies is to execute and enforce the laws of the U.S. government. The federal agencies must update their rules and regulations in the Code of Federal Regulations (C.F.R.) to abide by any changes to the U.S.C. Besides updating the C.F.R., the federal agencies can also make changes to their internal policy documents.
Since 1973, there have been over 11,000 enacted public laws averaging about 500 per year. The U.S.C. alone contains over 47,000 pages of text and over 43 million words. In addition, federal agencies and various departments issue around 8,000 federal regulations each year. Accordingly, the collective legal corpora are immense, complex, and constantly changing.